Torque converter interlocking control, automatic



June 22, 1943- H. o. SCHJOLIN TORQUE CONVERTER-INTERLOCKING CONTROL, AUTOMATIQ Filed Sept; 1, 1938 6 Sheets-Sheet l Snventor Jfazar 0.62% 9L attorneys June 22, 1943. H. o. SCHJOLIN I 2,322,479

TORQUE CONVERTER-INTERLOCKING CONTROL, AUTOMATIC Filed Sept. 1, 1958 6 Sheets-Sheet 2 Enventor JKazmscqb/zzz June .22, 1943. H. o. SCHJOLIN TORQUE CONVERTER-INTERLOCKING CONTROL, AUTOMATIC Filed Sept. 1, 1938 6 Sheets-Sheet 3 A Ihwe ntor 762m 0. Jc/z 0/22? June 22, 1943. o, SCHJOLIN 2,322,479

TORQUE CONVERTER-INTERLOCKING CONTROL, AUTOMATIC Filed Sept. 1, 1938 6 Sheets-Sheet 4 Inventor June 22, 1943. H. o. SCHJOLIN 7 TORQUE CONVERTER-INTERLOCKING CONTROL, AUTOMATIC Filed Sept. 1, 1938 v 6 Sheets-Sheet 5 June 22, 1943. 1-1. 0. SCHJOLIN 2,322,479

TORQUE CONVERTER-INTERLOCKING CONTROL, AUTOMATIC Filed Sept. 1, 1958 6 Sheets-Sheet 6 ZSnventor JKa w 0. sv/ az kz Patented June 22, 1943 TORQUE CONVERTER INTERLOCKING CONTROL, AUTOMATIC Hans 0. Schjolin, Pontiac, Mich., assignor, by mesne assignments, to Yellow Truck & Coach Manufacturing Company, Pontiac, Mich., a corporation of Maine Application September 1, 1938, Serial No. 227,926

(Cl. 192--.0l)

35 Claims.

The invention relates to motor vehicles, more particularly of the type in which specialized grouping of the driving mechanism and of the controls is required for the operation of large vehicles such as busses or trucks, wherein the drivers station may be located at some distance from the power plant.

The invention relates specifically to the automatic controls for the driving mechanism whereby the driver, by manipulation of a single control member, may compel continuously the selection of drive at the highest speed ratio or in reduction ratios.

The invention relates also to auxiliary control devices whereby the driver may interrupt the automatic functioning of the controls at any time and compel operation manually.

The invention relates likewise to a control system in which the necessary force for performing the control actuation is furnished by auxiliary power means such as fluid pressure motors supplied from a reservoir or its equivalent, and relates to quickly responsive relays which enable the control mechanism to function surely and rapidly.

The invention also relates to a system of controls for relays involving electro-pneumatic means interlocked through a switch system which provides for the relief of torque momentarily in the operation of positively driving clutches used for establishing and releasing drive for certain shift actions of the driving mechanism.

An outstanding advantage of the invention is the method for compelling, by overtravel of the drivers accelerator pedal, an immediate downshift from the highest ratio to the lower ratios upon full depression of the pedal.

An object of the invention is to provide a single driver-operated control member for compelling continuous selection of drive at high or reduction speed ratios in the mechanism described above. A further object is the provision of automatically selected speed ratios therein, wherein auxiliary control devices enable the driver to interrupt automatic selection at any time, and compel manually selected operation. An additional object is to provide auxiliary power means controlled by relays for carrying out the automatic and manual control functions described. It is likewise an object to provide a control system having means for the relief of torque momentarily during the shifting of positively driving clutches used for establishing the various ratios herein. It is an important object to provide a ratio shift compelling means controlled by movement of the engine accelerator pedal for immediate downshift from the highest to the lower ratios upon full depression of said pedal.

In the demonstration herewith the invention shown is applied to a form of drive in which a hydraulic torque converter yields infinitely variable speed ratios for torque multiplication and direct positive drive between the engine and the output shaft for the highest ratio without the intermediary of a friction clutch or its equivalent. The disclosure herewith also shows control means arranged in an interlocking system between the elements for selecting ratio automatically and the elements for establishing the relief of itorque for synchronizing and changing speed ratio, so that the system is protected against wrong motion.

Additional advantages appear in the present application wherein the operating requirement for coordination of foot and hand controls normally utilized is supplied by the automatic control means, which includes the auxiliary power devices as noted preceding. Further objects and advantages are described by the following detailed specification given to accompany the drawings where:

Figure 1 is a schematic view of the installation of the driving mechanism controlled by my invention, applied at the rear of a motor bus chassis, the power plant being arranged transversely.

Figure 2 is a longitudinal view of the power plant of Figure 1 taken in part section in the longitudinal plane.

Figure 3 is a vertical section of the electromagnetically operated control valve designated by the letter V in the following description.

Figure 4 is a diagram of the electric circuits and control elements for the automatic shift and synchronization control as applied to the construction of Figure 2.

Figure 5 is a repetition of elements of Figure 4 showing the relative positioning of the control elements thereof during the interval of shifting from drive through the converter to direct drive.

Figure 6 is a view similar to that of Figure 5 showing the control elements as positioned for direct drive.

Figure 7 shows the control elements as they are positioned for the shifting down interval from direct, to drive through the torque converter.

Figure 8 illustrates the relative positions of the control elements during the interval when the operator is overruling the governor and compelling downshift from direct to the reduction ratios.

Figure 9 is a control diagram similar to that of Figure 4 but including the operator's forwardneutral-reverse compelling mechanism wherein a master control associated with the handlever may interrupt the electrical circuits involved in the automatic shift and automatic synchronization controls.

Figure 10 shows the detail of construction in section of the gear-lever ball of Figure 9.

In Figure l, the driving mechanism installed in the rear of a passenger bus is arranged transversely, the engine at the left, the driving mechanism at the right, andthe final output drive shaft being in the fore-and-aft plane of the vehicle connected to conventional differential drive for the vehicle rear wheels.

The engine is of conventional type, and its power is delivered to the output shaft directly through positive drive clutch D or indirectly through turbine'clutch C and a turbine type torque converter T acting as an infinitely variable transmission for reduction speed ratio drive, a gear assembly R in which is incorporated an overrunning clutch F arranged coaxially with respect to the engine shaft.

The propeller shaft 68 extends forwardly and down to drive the conventional differential gear shown in outline in Figure 1 at W. The engine is conventionally indicated at A in Figure 1; the

clutch operator mechanism being designated by letters MI and M2, described fully further on in this specification;

The transmission control elements of Figure 1 are shown in detail in Figure 2. The engine crankshaft I drives the engine flywheel in the customary manner and likewise solid shaft 2, which extends through the entire length of the gear box 26, mounted in appropriate bearin s.

Adjacent the engine shaft I is spline 3 of shaft 2 upon which slider 4 is mounted. At the right end of Figure 2 shaft 2 is shown splined at 5 to clutch Hub 6, and to flange fitting 8 which drives the accessory units including the air compressor of the vehicle.

Sleeve 9 is mounted for rotation and surrounds shaft 2 for part of its length, being splined to bevel gear body I having teeth I2 meshing with the teeth of bevel gear I4 attached to or integral with propeller shaft 68.

Slider 4 may be moved by yoke III from rocking of shaft 68 through lever I outside the casing 20, and its teeth I3 may mesh with integral teeth II of gear body I0 rotating the shaft 9. Cut on the body of slider 4 are two rings of teeth 54 and 55, shown in detail in Figure 9, teeth 54 engaging balking ring 53 loosely, so that the ring may have limited lost motion rotationally through its teeth 53a. The ring 53 extends in a radial flange having frictional bearing with a face of collar 56 splined to the inner portions of teeth I I. Spring 59 exerts constant tension between that portion of the slider'which carries teeth I3 and balk ring 53, so that there is always constant loading of the faces of ring 53 and collar 56.

Lock ring 52a of Figure 8 prevents the backing off of ring 53, restraining it to move longitudinally in the space between it and the collar 56.

When the yoke 10 is moved to apply an engaging force to slider 4 for the teeth I3 to mesh with the teeth II, frictional drag collar 56 bearing on ring 53 applies a rotational component to the ring so that the facing portions of teeth 53a of the ring block the longitudinal motion of the I30 and I25 fed with air pressure from pipe I24.

Porting in cylinder I38 connects to pipe I22 which feeds cylinder I25 as is explained in detail later.

Clutch D has fork I0 fixed to rod II mounted to slide longitudinally in extensions I2 of casing 28, the stop I3 and spring 14 normally acting to load the slider 4 for rightward or engaging movement. Lever I5 pivoted to the casing at 69 may normally rock to remove the force of spring I4 and separate the teeth I3 from teeth II of the direct drive clutch D, under the motion of pivoted piston rod 16 and piston I48 through the superior force of springs 11 in cylinder I30. Admission of air pressure from pipe I24 to the face of piston I48 overcomes the force of springs I7 and permits spring I4 to load slider 4 for engaging direct drive, which, as has been stated, occurs at synchronism with full mesh of teeth I3--I I.

The second cylinder I25 houses piston I52, sprin s I49, and rod I45, pivoted to lever 46 of shaft 41 arranged to shift fork 44a and bearing sleeve 44 of clutch C.

Clutch C has hub 6, flange 6a, extension 39, and slidable presser plate 36, the disc spring 42 being guided in a groove 44b of bearing sleeve 44, its outer edge being held by a lip of extension 39. The presser plate 36 has fulcrum portion 36a which bears against spring 42, so that servo pressure in cylinder I25 will unload the spring 42 from plate 36, and clutch driven disc 48 will cease to be gripped between plate 36 and flange 6a. When air pressure is removed from cylinder I25, spring I49 shifts piston I52 and rod I45 to the left, rocking lever 46 clockwise, and shifting sleeve 44 to the right, as in Figure 2, and disc 42 past center to loading position as shown in the figure, wherein plate 36 grips clutch driven plate 48 to rotate with flange 6a and shaft 2. Fork 44a shifts sleeve 44 when shaft 41 rocks.

As will be explained further, the air pressure is furnished to pipe I24 from a single control valve V operated by a vehicle speed governor G described in connection with Figures 4 and following.

When air is supplied to both cylinders, the direct drive clutch D is permitted to be engaged, and the turbine clutch C is unloaded. When air is withdrawn, the direct drive clutch D is disengaged, and the turbine clutch C engaged. The sequential control action by which the transitions between direct and turbine drives are accomplished are an important part of the invention, as will be understood from the following description.

The turbine unit primary member is vaned impeller 40 attached to sleeve 34 which may be driven by driven clutch plate 48 from shaft 2 at engine speed. Turbine vaned rotor 30 receives the torque delivered by the unit, transmitting it through attached sleeve I5 to splined gear I6 meshing with countershaft gear 2'! through reverse idler 32, and through affixed roller clutch member I8, one-way locking rollers I 9 and external clutch member 2I. The reaction-bladed member 50 of the turbine affords multiplication of torque in the customary manner in such devices, by virtue of the relationship of its blading with respect to the vanes of the impeller 40 and the rotor 30. Blades 50a and 50b are part of reaction member 50. Blades 3| and 3|a rotate with the output rotor 30 as is customary in such constructions. Seals I95 and I91 only are required to prevent loss of liquid from the turbine compartment.

Hollow shaft 9 is splined to gearbody I which drives output shaft 60, and carries ring of teeth 23 longitudinally aligned with gear 28 of countershaft 29 to which gear 21 is aflixed. Slider 25 moved by fork 95 has external ring of teeth 26 meshable with 28, and internal teeth 2| meshable with 23, in which position reverse rotation is imparted from rotor 30 and shaft I5 through train IIi--32--2128--26--252 I '23 to shaft 9.

When the slider 25 is in neutral, no engagement of gears 2823 through slider 25 is possible.

In right-hand position in Figure 2, slider teeth 2| mesh with teeth 22 cut on the outer surface of roller clutch race 2|, so that rotation of rotor 30 is imparted through shaft I5 to member I8, and through rollers I9 to race 2|, and to slider 25.

A second ring of teeth 24 on sleeve 9 adjacent teeth 23 is meshed with teeth 2| of slider 25, so that with the engine driving, the torque of rotor 30 is delivered from slider 25 through teeth 2| and 24 to shafts 9 and 60. When the engine is decelerated, the vehicle may coast and rotor 30 may idle. Should clutch C be disconnected, the turbine impeller 40 and rotor 30 both come to rest, because of freewheel clutch F.

Fork 95 is manipulated by shaft I I0 of Figure 9 to which it is aflixed; by lever IIO' outside the casing 20. and rod I09a, bellcrank I09, rod I08a, bellcrank I08, and rod I01. The remainder of the manual control connections of Figure 9 include the operator's shifter lever I00, linked with rod I01 through proper connections such as lever I04 moved with lever I00, link rod I05 and bellcrank II6.

Figures 3 and 4 show the master controlling valve for the clutch servo system of Figure 2, connected through pipe I to a reservoir of air pressure (not shown), supplied by the conventional automatic pump, common in buses and trucks of the present day. The outlet pipe I24 from valve V feeds both cylinders I25 and I of Figure 2, as is described further in detail. The exhaust connection to atmosphere is shown at I34a.

The assembly of valve V comprises a casing 20I enclosing sliding valve stem member I26 in bore I26a drilled out centrally in sleeve I32, and cross ported at I33 to register with exhaust port I34 leading to pipe I34a; an air valve I42 is arranged to seat in plate I44 at I44a, to seal off passage of air pressure chamber I2,I connected to inlet pipe I20.

Cylindrical ring I3I embodying seat MI is set in the casing 20I and separates the servo outlet chamber I2Ia from the exhaust space about the upper portion of I26 above seat MI.

The stem of valve I26 projects upward into recess of solenoid coil I15, acting as an armature for moving the valve when current is furnished to the coil I15 from external circuits to be described.

Spring I43 rests under the air valve I42 tending to hold it firm on seat of plate I44, sealing off chamber I2| from I2Ia.

When current is applied to coil I15, the armature portion I26 is drawn down by the flux field generated, shifting the valve V against the tension of spring I43. This causes the valve action between |26-|4I to seal at seat I4I, preventing atmospheric leakage to port I34, and the lower valve I42 becomes unseated by servo line pressure, admitting compressed air from line I20 and chamber I2| to space I2Ia and pipe I24.

While current is flowing in the circuit of coil I15, as will be described, the air reservoir is constantly connected to servo feed pipe I24 and thereby to cylinders I25 and I30.

When the current circuit is broken, the spring I43 is allowed to shift I26 and I42 upward, sealing off the compressed air supply from the servo cylinders I25 and I30, and connecting them to exhaust. Member I42 abuts the lower end of stem 46 during this action.

Figure 4 shows a conventional engine carburetor I50, the throttle valve of which is 'moved by lever I5| pivoted to rod I52, and solenoid arrnature rod I53. Solenoid I55 is mounted conveniently on the engine. Lost motion connection is established between the accelerator rod I54 and rod I52 through cylinder I56, disc I51 attached to rod I52, and spring I58, the operators accelerator pedal I60 and rod I6I being connected through bell-crank I62 to rod I54. The motion of rod I54 is also imparted to stop I65 fixed to rod I54 for purposes which will be stated later.

Governor G is of conventional type, receiving drive from shaft 60 of Figure 2 through appropriate gearing I68 of Figure 2 to shaft I69, the sliding collar I10 carrying contact HI, and contact I12.

Control valve V is mounted at any convenient point on casing 20 and consists of a construction as shown in Figure 3, operated by solenoid coil I15 and armature I26.

Cylinders I25 and I30 are shown in detail in Figure 2, the piston rods I45 and 16 controlling the actuation of the clutches C and D as described.

In the diagram of Figure 4, shaft 2 is driven by the engine as shown in Figure 2, and carries splined jaw clutch slider member 4, the teeth I3 being meshable with the teeth II of gearbody I0 which drives gear I4 and shaft 60 as shown in Figure 2. Fork 10 attached to shaft 1| may shift member 4 to engage and disengage the teeth I3--I I. Spring 14 normally biases shaft 1| to load slider 4 of clutch D for engagement with the teeth II of gearbody I0. Lever 15 is adapted to shift slider 4 out of engagement by the force of springs 11 of cylinder I30 tending to shift piston I48 and rod 16 to the right, but when air pressure is admitted behind the piston I48, from pipe I24, the load of spring 11 is overcome, and spring 14 is then permitted load slider 4 for engagement of teeth I3 and II.

Port I23 located at a. distance along the barrel of cylinder I30 received no air pressure from line I24 and valve V until the piston I48 is moved to uncover it, at which time the direct drive clutch D is fully loaded by springs 14.

The air reservoir of the vehicle is connected through pipe I20 to pressure space I2I of casing 20| of valve V. The outlet port I2|a of valve V is connected to pipe I24 joined to cylinder I30.

The clutch C is operated as described in connection with Figure 2 by piston I52 and rod I45 in cylinder I25, housing spring I49.

The electric interlocking circuit is composed of battery B shown in the diagram connected to governor collar I10, which may contact points I16 or I11, through I1I or I12. Switch point I19 of switch S may deliver battery current from I16 to the solenoid I15 of valve V, the other connection of the solenoid being grounded on the frame of the vehicle so that a circuit may be completed back to the opposite pole of the battery. Point I11 also delivers current to point I8I of switch S The upper governor contact I16 is connected to armature I80 of switch S Point I19 of switch S connects to solenoid I15. Point I82 of switch S is joined to the first circuit described through connection I84 50 that it may break current also used to operate solenoid I15.

The armature I85 of switch S which is rocked by intersecting slot No of shaft 1| is connected to throttle control solenoid I55, which in turn is grounded on the frame of the vehicle. Armature rod I53 of the solenoid is restored by spring I550:

, when the current in I55 is cut ofi.

The drawing of Figure 5 shows the relative positions of the controls when shifting from the drive of the torque converter to direct drive, at

which time the balking action of member 53 oi clutch D of Figure 2 is being exerted. The governor G is connecting the battery circuit contact I16 to armature I80 of switch S, the battery current to point I19 and to the solenoid I15 of valve V, This admits fluid pressure to line I24 and cylinder I30, causing piston I68 to move to the left of the figure and rock lever I5 against the action of springs 11. During this interval spring 14 is endeavoring to load clutch D for engagement. Battery current through connection I84 is being delivered also to point I82 of switch S and through the armature I85 and connection I86 to throttle controlled solenoid I55 so that the engine throttle is reduced to idling position in order to assist in the synchronization action of clutch D.

As soon as synchronization is completed, and the teeth I3-II are seated, shaft 1I moves to rock armature I85 of switch S anticlockwise, disconnecting the battery current from throttle controlled solenoid I55, which action restores full control of the engine throttle to the car d.iver, through pedal I60.

In Figure 6 the system is shown at the point when the armature I85 and contact I8I had just Leen connected for establishing direct drive.

In Figure 6 the governor is shown in the same position as in Figure 5, but the switch S has been tripped by shaft 1I so that the carburetor throttle arm I5I is no longer restrained by the solenoid I55, and spring I58 of the lost motion connection has restored the normal position of: .rod I52 with respect to rod I54. Throttle return spring I550. is weaker than the lost motion spring I58.

-In Figure 7 the arrangement of parts is for the purpose of illustrating the normal operating condit ons of the control elements when the governor is causing shifting down from direct drive through clutch D of Figure 2 to torque converter drive through clutch C of Figure 2. In this view, the governor G has disconnected from contact I16, and has connected contact I11 so that the battery current may flow to the point I8I of switch S and to point I18 of switch S The battery current is relieved from solenoid I15 of valve V, permitting the air pressure to exhaust from the face of piston I48 of cylinder I30 through the exhaust port I34 of valve V, and likewise to exhaust from the face of piston I52 through connecting pipe I22 and port I23 through the atmospheric connection about the rod 16 of piston I48 in cylinder I 30.

During the period of shift from clutch C to clutch D, when the synchronism dwell is necessary to obtain proper operation of clutch D, it is useful to maintain clutch C in driving engagement until the jaws of clutch D are nearly at synchronous speed. To accomplish this, pipe I22 must receive its pressure from valve V and line I24 through port I23 located along the barrel of cylinder I 30, some distance from the full stroke position of piston I48. The incoming air pressure then has to shift I48, rod 16 and lever 15 to a position where the force of spring 11 is taken away, and lever 15 permits spring 16 to shift rod II to the right, assuring loading of clutch D before clutch C is unloaded, and putting a timing delay in the release of clutch C. On the other hand, during engagement of clutch C it is desirable to accelerate the release of air pressure from cylinder I25 so that clutch C may come in reasonably quickly; therefore, the porting of air release from I25 through I22 and I23 to the atmospheric side of piston I48 enables this to be accomplished.

When the governor has moved to the position shown in Figure 7, it is for the purpose of disconnecting clutch D, therefore with the removal oi air pressure from the face of piston I43, springs 11 of cylinder I38 will exert a thrust on piston M8 to the right, rocking lever 15 so as to stress rod II for leftward motion, against the action of spring 14. The resultant of this action is to endeavor to disconnect the jaw clutch teeth I3I I. Since torque on the flat sides of the jaw clutch teeth may interfere with the separation of teeth I3II and release of drive, the governor circuit through switch S is established through connection I88, point I8I, armature I85, and connection I86 to solenoid I for reducing the engine throttie to idling position momentarily, or sufllciently long to relieve the engine torque from the teeth I3I I. I

Immediately upon the accomplishing of the release motion, slot 1Ia of rod 71 will snap the armature I85 of switch S so as to disconnect the solenoid I55 and thereby restore control of the engine throttle to the operator's pedal I60.

Figure 8 is to illustrate the action of the control elements whereby the driver, by moving the engine throttle pedal I past full throttle position, may cause the automatic downshift from direct drive to' converter drive to take place.

Accelerator connected rod I54 has attached stop I which in ordinary throttle operating ranges will not interfere with the action of armature I of switch S However, at beyond full throttle the stop I65 will strike the armature I80, disconnecting the circuits beyond point I10, and connecting point I18 of switch S through connection I89 to point I8I of switch S In breaking the connection at point I19, the current which has been flowing through solenoid I15 of valve V is interrupted and the valve spring I43 causes the fluid Pressure in pipes I24 and I22 to exhaust by shifting the valve members I26I 42 of Figure 3 to exhaust position.

It will be seen that here again springs 11 of cylinder I 30 will force piston I48 to the right, causing lever 15'to rock counterclockwise in order to accomplish disengagement of clutch D. As before, solenoid I55 operating throttle control lever I5I is momentarily energized to remove the engine torque load from teeth I3I I, as described in connection with Figure 2.

In Figure 9 the operator's control for forwardneutral-and-reverse shift is shown in the upper right corner wherein lever I pivoted at I02 to the dash of the driver's compartment may rock lever I00 pivoted to rod I05, in turn pivoted to bellcrank H0, which shifts rod I01 right or left, as the handlever I00 is moved toward the top or the bottom of the drawing, about I02.

At the rear of the vehicle, rod I01 is pivoted to bellcrank lever I00 mounted on the frame and attached to rod I000 pivoted to bellcrank I00 which in turn shifts rod l00a attached to shifter lever IIO' fixed to shaft IIO projecting from the gearbox. Referring back to Figures 1 and 2, it will be seen that fork 05 moved by shaft H0 and leverI I0 may connect the drive for forward or reverse, yielding neutral or no-drive in midposition.

The vehicle battery B, in addition to being directly connected to the master control of governor G, is in Figure 9 shown connected through wire I00 to push button switch El mounted in the ball I00a of gearshift lever I00. The spring I05 normally separates contact I06 from contact I01 so that the battery current may not flow to conductor I00 leading to the solenoid I15. Figure 10 show the detail of construction of the gear lever ball switch.

When the button I00 is pressed, the battery circuit is applied by the connection of contacts I00 and I01, 'so that the operator may at any time connect the current to the solenoid I shiftin the valve V to servo position, filling cylinders I and I30. This will overcome spring I40 of cylinder I25 to load clutch C for disengagement, and allow spring 14 of rod 1| to load clutch D for engagement; so that the resumption of drive after the button I08 i released may occur with the torque converter clutch engaged, with the clutch D in balking position, only with button I08 down.

This momentary admission of air pressure serves to relieve the inertia and drag of the fluid converter unit from the drive, and facilitate the shift between forward, neutral and reverse with slider 25 of Figure 2. The method of manual control for facilitating shift is believed novel and useful in the handling of high inertias.

It is believed proper to sum up the manifold advantages of my construction wherewith the statements made in the introductory portion of this specification have been substantiated by the description. In the description of operation, the foregoing specification has pointed out the method of control giving complete mastery to the driver for all normal forward drive operation through the accelerator pedal coaction with the coordinating means involving the action of the circuits established through switches S S solenoid I55 and electro-pneumatic valve control I15.

The lost motion connection between rods I52 and I50 of the throttle linkage serves the useful purposes of allowing the intervening means connected through solenoid I55 to retard the throttle and move it to engine idling position, while the ratio changing means is performing predetermined shifts through the actuating aiforded by the fluid pressure servo motor devices, the interrelationships of the clutch loading and biasing means serving to accelerate the time interval of shift or hasten the interval of rejection of mesh of the jaw clutch devices, among other objects.

mechanism through the power means control, and the auxiliary gear lever button switch I 00 is likewise of great utility in the expediting of the responses which augment the safety and sureness of the controls in general. The applicability of this control system to the broad problem of mastery of the peculiar combination drive involved in the fluid torque converter used herein as a hydraulic drive unit yielding pure multiplied torque for reduction drive, is believed well demonstrated.

In ordinary controls for infinitely variable transmission it has been customary for inventors to devote their effort at automatic shifting to devising variable ratio interlock control means. This is well demonstrated in the prior art. The present invention, however, provides a control which takes into account the self -regulating ratio characteristic of the modern fluid torque converter, and which masters the intervals of shift between the torque converter path and the direct driving path of torque. The efllci ency and speed of action of such a required control are important factors in large vehicles such as busses, wherein' the sureness and safety of the control means given the operator are believed of high order in the present demonstration.

Attention is directed to the fact that the described automatic controls for forward driving in the present demonstration provide equally for reverse drive, since the elements of the control system at large, continue to function in the described manner when the drive between shafts 2 and 0 passes through the reverse idler gear 32 and countershaft gear 21. It is possible with the described controls to install the invention in a specialized type of vehicle capable of continued drive in either forward or reverse directions, as is required in the field of farm machinery and soil handling equipment, as will be obvious to one skilled in this art. The example given herewith applied to a rear-engined bus is to comply with the requirements for adequacy of showing, and in no way limits the scope or utility of the invention.

Now having described the invention and a preferred embodiment thereof, it will be understood that the scope of the same is not to be liinited to the specific details herewith described, but must be understood in the light of the claims which follow.

I claim:

1. In combination, an engine connected to a power shaft, a load shaft, an accelerator pedal controlling the speed of said engine, a variable speed transmission comprising a fluid torque converter adapted to transmit drive between the shafts, clutching means for connecting said transmission to drive therebetween, further clutching means for connecting said shafts directly when said first named means is disconnected, fluid servo motor devices for operating both said means, control mechanism including a speed responsive governor for selecting the operation of said devices upon said means, and means operable upon predetermined motion of said pedal whereby said mechanism is caused to change the drive from the second to the first of said means.

2. In combination, an engine, an accelerator pedal controlling the speed of said engine, a throttle linkage moved by said pedal, a power shaft and a load shaft, a variable speed transmission connecting said shafts embodying a clutch arranged to transmit drive directly between shafts at one-to-one ratio, a shifting mechdrive between said shafts, a shifting mechanism for operating the clutches of said variable speed transmission, a governor controlling said shift- 'ing mechanism, and a member arranged in the for said transmision, power means adapted. to.

shift said throttle to engine idling position against the manual effort applied to said pedal by overcoming said spring while establishing lost motion through said connection, a control for said power means, and connecting means between said shifter means and said power means control effective to reduce the engine throttle for predetermined operating conditions of said shifter means.

5. In motor vehicles, in combination, a variable speed changing transmision embodying at least one positive-jaw driving clutch, ratio shift mechanism for said transmission and operative to connect and disconnect said clutch, controls for said mechanism, an engine throttle, means controlling said throttle and controlled by said ratio shift controls for moving the throttle to low,speed position when the said controls are set and effective for releasing the drive of said clutch, and means associated with the said mechanism and said first named means effective to restore normal throttle operation upon completion of release of the said clutch.

6. In motor vehicles, in combination, an engine, an engine throttle, a manually operable device for controlling said throttle, a power shaft, a load shaft, a fluid torque converter adapted to transmit power between said shafts, shifter mechanism for establishing drive through said converter or directly between said shafts, and means governed by the movement of said mechanism for preventing manual actuation of said device for predetermined conditions of operation of said mechanism.

'7. In motor vehicle power controls, a power shaft, a load shaft, a variable speed transmission coupling said shafts, shifting means in said transmission for establishing forward or reverse drive or neutral, a shifter control for said means, ratio changing means in said transmission operated by fluid pressure, a valve for controlling the fluid pressure to said means, a positive jaw clutch included in said ratio changing means, and an auxiliary manual control for said valve effective to energise the fluid pressure motor means when said shifter control is m ved 7 shift said shifting means, the action of said manual control assisting in the completion of the shift to either neutral or reverse by said shifter control.

8. In motor vehicles, in combination, a throttle controlled engine, an accelerator pedal, a throttle lever, a return spring for said lever, a throttle rod pivoted to move said lever for varying the speed of said engine, a throttle controlling electrical circuit, energising control means for said circuit made operative by movement of said pedal, a solenoid for shifting said throttle lever against said spring to engine idling position when said circuit is electrically energised, and a yielding lost-motion connection between said pedal and said rod, said connection yielding upon energisation of said circuit by said pedal with corresponding response of said solenoid in shifting said lever to idling position.

9. In motor vehicles, in combination, an engine, an engine throttle, an engine accelerator pedal, a power shaft, a load shaft, variable speed mechanism connecting the shafts embodying positive direct drive establishing means and a second path of increased torque through a hydraulic torque converter made effective by a second engageable and disengageable driving means, actuating means for both said driving means controlled jointly by a speed governor deriving rotation from one of the shafts and said pedal, and coordinating means for said controls connected to said first named means effective to assist in the connection and release of said direct drive for predetermined shifts of said actuating means made according to the control actions of said pedal and said governor.

10. In motor vehicles, in combination, an engine, an engine accelerator pedal, a power shaft, a load shaft, a variable speed transmission connecting said shafts, fluid pressure motor means for changing the drive of said transmission between reduction ratios and direct drive, a control mechanism for said means, a governor for said mechanism'eifective at a predetermined speed of one of said shafts to initiate shift of the fluid pressure motor means for changing from variable reduction to direct drive of said transmission, and connecting means joining said mechanism and said pedal effective when said pedal is moved to a predetermined position to initiate a shift of said first named means from direct drive to variable reduction ratio drive by said transmission.

11. In combination, a motor vehicle driven by a throttle controlled engine, an accelerator pedal, a power shaft and a load shaft, a variable speed ratio device embodying direct drive and reduction ratio drive, shifting means for transmitting power between said shafts, control mechanism for said device comprising means responsive to said pedal position and said vehicle speed, effective to select direct drive or reduction drive by said device,, and a throttle retarding means operated by said mechanism for predetermined shifts by said first named drive shifting means in response to movement of said mechanism- 12. In variable speed gearing controls for motor vehicles, in combination, an engine, an engine throttle, manual means for operating said throttle, intervening means adapted to close said throttle against the action of said manual means, a variable speed transmission driven by said'engine embodying a positive jaw clutch device composed of asliding jaw and a relatively fixed mating jaw, a friction balking member for said sliding jaw adapted to prevent mesh of said Jaws except at synchronism, loading means for said member operative to establish constant friction between the member and the said fixed Jaw, a slider for said sliding Jaw, an operating device .for said slider embodying a preloaded force applying mechanism, and connecting means between said device and said throttle intervening means effective to close said throttle for predetermined movements of said operating device.

13. In motor vehicle controls, a combination, an engine, a power shaft, a load shaft, an engine throttle, a manual control for said throttle, a solenoid arranged to shift said throttle to idling position when energised, by electric current, a variable speed transmission controlled by upshift and downshift electrical circuits operating clutch control mechanism and including fluid pressure actuation cylinders for said mechanism, a governor driven by said load shaft having electrical contacts adapted to close the upshift or a downshift controlling circuits, a solenoid valve normally arranged to prevent fluid pressure from being exerted in said cylinders, connections between said governor contacts and said valve whereby said valve is opened to apply pressure to said cylinders when the upshift circuit is closed, and a control for said throttle operating solenoid worked by the actuation of said clutch control mechanism for predetermined movements of said governor and of said manual control.

14. In power controls, in combination, an engine throttle, a variable speed transmission embodying a jaw clutch, a slider control mechanism normally biased to load said clutch for engagement, a lever arranged to interfere with the biasing action of said mechanism, fiuid pressure means for rocking said lever to non-interfering position with respect to said mechanism, and means operated by motion of said mechanism for retarding the engine throttle when the fluid pressure means is rendered inactive.

15. In motor vehicles, in combination, a load shaft, 9. primary power shaft, a secondary power shaft, transmission means associated with said shafts embodying a train of driving elements including a pair of alternately operated clutches, one of said clutches comprising two positive jaw members carried respectively on said two first namedshafts, said train also including a fric tion clutch adapted to connect said load shaft and said secondary power shaft, an auxiliary device arranged to permit and prevent mesh of said first named clutch members according to synchronous speeds of the two first named shafts, power means effective to alternate operation of said two clutches, a control for said power means, controlling means for said con trol, and connecting means between the control means for said control and said device effective when said control is moved to predetermined positions to accelerate the time interval required by said device to permit completion of mesh by said first named clutch members.

16. In motor vehicle power controls, an engine, an engine throttle, an engine shaft, a load shaft, a positive jaw clutch coupling said shafts embodying an element adapted to permit or prevent mesh of said clutch, actuation means for said clutch, a governor operating at the speed of one of the shafts arranged to control the said actuation means; and connecting means between said throttle and said actuation means operative to close said throttle to idling position for predetermined control movement of said governor applied to said actuation means for said clutch, whereby the interval of rejection of mesh of said clutch by said element is shortened when said clutch is being loaded for engagement by said means. 1

17. In power controls, in combination, a motor vehicle, an engine, an accelerator pedal for said engine, a first shaft connected directly to said engine, a second shaft connected directly to the vehicle load, mating positive clutch jaws adapted to couple said shafts, a constantly loaded friction element adapted to prevent, or to permit, mesh of said jaws in accordance with synchronous speeds of the two shafts, a control mechanism for engaging and disengaging said jaws embodying a loading means of predetermined force, an actuating means for said mechanism including a biasing means of superior force to that of said loading means and normally active to hold said loading means from being exerted on said mechanism, and a power means controlled by movement of said pedal adapted to overcome said biasing means and permit said loading means to become effective upon said control mechanism' for loading said jaws for engagement whereafter in the sequence of operation said friction element permits said jaws to engage at synchronous speed.

18. In power controls, in combination, an engine, an engine throttle, an engine throttle control, a power shaft carrying a movable positive clutch element, a load shaft carrying a mating clutch element, a constantly loaded friction element adapted to permit engagement of said first two elements at synchronous speeds of the shafts, shifting means controlling the engagement of said elements, coordinating means effective to cause the shifting means to move toward engagement of the said first two named elements while moving the engine throttle to engine idling position, and further means operative upon synchronous speed completion of mesh of said first named element with said second named element to disconnect the said coordinating means from further effect upon said engine throttle.

19. In motor vehicle controls, an engine, an engine-speed controlling pedal, a variable speed transmission including a direct driving clutch and a clutch for establishing variable ratio reduction speeds through a hydraulic unit, control mechanism for said clutches, a governor normally arranged to select the action of said mechanism for establishing drive through the hydraulic unit at low speeds or direct drive at high speed ranges, and an overcoming control worked by said pedal and operative on said mechanism adapted to set aside the high speed direct drive action of said governor, and compel variable reduction ratio drive through said hydraulic unit at the will of the operator.

20. In motor vehicles, in combination, an engine and a throttle therefor, control means for said throttle, a power shaft driven by said engine, a load shaft, a variable speed ratio drive embodying one path of torque between said shafts for driving said load shaft at variable reduction ratios, and embodying a second path of torque in which a positive jaw clutch couples said shafts d rectly, controls effective to establish said paths of torque alternately for reduction drive or for direct drive including a mechanism for shifting said clutch to driving and non-driving position, and means moved by said mechanism preloaded for release of said clutch and simultaneously operative upon said throttle control means to reduce the setting of said en'- gine throttle toward idling position, thereby relieving the torque on the teeth of said jaw clutch for diminishing the force requirement for shifting said mechanism.

21, In motor vehicles, in combination, an enthe action of said ratio selection means, and

likewise effective to reduce the engine torque applied to said clutch by said engine connected shaft when said mechanism is being shifted to disengage said clutch in accordance with the action of said ratio selection means,

22. A device as claimed in claim 21 wherein the clutch is composed of driving and driven members and an intermediate friction-responsive member adapted to prevent mesh of said members at dissimilar speeds, and permit mesh thereof at synchronous speeds.

23. A device as claimed in claim 21 wherein the shifter mechanism transmits force for shifting said clutch through a resilient means.

24. A device as claimed in claim 21 wherein the ratio selection means is connected to the said shifter mechanism through the agency of a relay controlled by said means, said relay directing the application of auxiliary power to the said shifter mechanism.

25. A device as claimed in claim 21 wherein the said shifter mechanism is actuated by auxiliary power means.

26. In motor vehicles, in combination, an engine, a throttle control for said engine, a change speed transmission for coupling said engine to a load shaft, embodying a jaw clutch arranged to take the driving torque on radial toothed faces, shifter means for said clutch, shift control mechanism for said means adapted to load said means for engagement and release of the drive by the said clutch, and means interconnecting said mechanism with said throttle control effective to reduce the speed of said engine and thereby reduce the driving torque on said toothed faces of said clutch in advance of said shifter means being loaded by said mechanism for release of the said drive by the said clutch.

27. A combination according to claim 4, characterized by means associated with said shifter means and said power means control effective to set aside the action of said connecting means upon completion of said predetermined operating conditions of said shifter means.

28. In a combination such as described in claim 11, the further combination of a throttle for said engine and means associated with said control mechanism adapted to restore normal operation of said throttle after said predetermined shifts by said first named drive shifting means shall have been made in response to movement of said control mechanism. 7

29. In a combination such as provided in claim 12, the sub-combination therewith of means associated with said device and said control means adapted to render the said throttle intervening means ineffective when said predetermined movements of said operating device are completed.

30. A combination such as described in claim 14, further including means associated with said mechanism and said retarding means effective to render said retarding means ineffective for predetermined movement of said mechanism. a 31. A drive control arrangement as characterized in claim 16 including means controlled by said actuation means during disengagement of said clutch effective to retard the said throttle upon the initial clutch disengagement action thereof and to restore normal operation of said throttle after the clutch disengagement action is completed.

32. In power control devices for motor vehicles, an engine, a load shaft, a transmission mechanism adapted to provide a direct drive between said engine and said load shaft and adapted to provide indirect drive therebetween when said direct drive is disconnected, said mechanism embodying positive driving elements arranged to,

couple said engine and load shaft and tending to resist disengagement thereof when drive is being transmitted between said engine and said shaft by said elements, shifter means arranged to apply force to'one of said elements for causing engagement and disengagement of said elements for changing the ratio of drive between said engine and said load shaft, a device adapted to diminish the torque of said engine and thereby unload the resistance to disengagement of said elements for facilitating release of drive thereof, and means controlling the disengagement action of said shifter means effective to cause said device to diminish the said torque of said engine prior to release of drive by said elements.

33. In variable speed ratio transmissions for motor vehicle drive, in combination, an engine, a power shaft driven by said engine, a load shaft, a transmission mechanism coupling said shafts at various speed ratios including a positive jaw clutch for coupling them at direct driving ratio, a balking member associated with said clutch adapted to prevent engagement of said clutch except when synchronism between said shafts exists, actuating means for said clutch arranged to apply engaging and disengaging force thereto for coupling and uncoupling the drive between said shafts, a device operative with actuation of said means and effective to diminish the torque of said engine and thereby unload the resistance to disengagement of the jaw elements of said positive jaw clutch when said means is set to disengage said clutch, and control means acting upon said device and said actuating means arranged to select speed ratio of said mechanism and actuation of said clutch by said actuation means for both engagement and disengagement.

34. In variable speed ratio transmissions for motor vehicle drive, an engine, an engine throttle, a power shaft driven by said engine, a transmission mechanism driven by said power shaft, a load shaft adapted to be driven by said mechanism, engageable and disengageable positive coupling means for said shafts embodied in said mechanism, control means for said coupling means and said mechanism, a speed responsive device operable upon said control means for selecting the drive of said mechanism and for causing engagement and disengagement of said coupling means, a pedal for said throttle connected to modify the operation of said device upon said control means, and additional means for reducing and then restoring the torque of said engine to facilitate the release of said coupling means when said control means is operating to disconnect said coupling means under the joint action of said device and said pedal.

35. In variable speed ratio transmissions for motor vehicle drive, an engine, an engine throttle, a power sliaft driven by said engine, a transmission mechanism driven by said power shaft, a load shaft adapted to be driven by said mechanism, engageable and disengageable positive coupling means for said shafts embodied in said mechanism, control means for said coupling means and said mechanism, a speed responsive device operable upon said control means for selecting the drive of said mechanism and for causing engagement and disengagement of said coupling means, a pedal for said throttle connected to modify the operation of said device upon said control means, and additional means for reducing and then restoring the torque of said engine to facilitate the release of said coupling means when said control means is operating to disconnect said coupling means under'the joint action of said device and said pedal, said additional means being likewise effective to reduce the torque of said engine upon the initiation of engagement of said coupling means and to restore same when said engagement is completed. HANS O. SCHJOLIN. 

